The present invention relates to an evaporating apparatus with heat regenerating system. More particularly, it relates to such an evaporating apparatus in which heat of vapor is at least partially converted into available heat with higher temperature without significant utilization of high energy and thereafter the thus obtained heat is utilized for the evaporating process itself or for another process.
Apparatuses of the above-mentioned general type are known in the art. Such apparatuses are utilized for evaporation processes in thermal equipment for evaporation of solutions or thermal separation of substances. They are utilized for reduction of primary energy consumption during thermal material separation processes by heat recycling with the utilization particularly of latent heat content of the vapor. The vapor of the last evaporation stage of a multi-stage apparatus is liquefied in jet-condensers, and the condensate is carried away into the atmosphere. In dependence upon the temperature of the evaporated solution the vapor in some cases can be partially condensed because it gives out heat to the solution to be preheated. Since, however, the vapor can transfer heat to the solution only for such time until the solution attains approximately the vapor temperature and the latent heat content of the steam is always greater than the heat quantity transferred during this process, the major part of the vapor heat is given away to the atmosphere without being utilized. When the temperature difference between the vapor of the final stage and the hot vapor for the first stage is not too great, and when the characteristics of the vapor allow, vapor compressors for the regeneration of process vapor can be introduced. However, in this condition the compressors require more energy than they can spare during their operation.